You may know that when it comes to birth control, there are quite a few options on the market. But what are they? How do they work? Are they effective?

Below and in related installments, you’ll find a comprehensive list of birth control methods, along with their function, failure rates, and if applicable, potential risks and side effects.


In this post, we will cover fertility awareness-based methods, which involve tracking ovulation (i.e. fertility) to minimize the chance of pregnancy. Also called natural family planning or fertility awareness, these methods do not employ other types of birth control (except perhaps on fertile days). For this reason, they are safe, inexpensive, and don’t have side effects. They can be useful not only to prevent pregnancy but also to plan pregnancy, since they employ an understanding of the menstrual cycle and when you are most likely to get pregnant (as well as moderately likely, moderately unlikely, and very unlikely). The information below will provide the basics of each method. It is important to talk to a healthcare professional about your options before using one of these as your primary method of birth control.


There are a few different types of fertility awareness-based methods. Overall, their typical failure rate is 24%, but this can be decreased dramatically by a combination of the methods, and correct usage.


Calendar Method: This method requires that a woman keep a record of her menstrual cycles, including the first day of her period and the length of the cycle. Through calculations using this record, she can determine which days she most likely to be fertile and infertile. However, this method cannot say for sure which days will be safe and unsafe, and therefore should always be used with other methods.

The Standard Days Method is a type of calendar method, which has a typical failure rate of just 5% when used correctly. Using the Standard Days method, you must have a consistent cycle of 26-32 days, and abstain from sex on days 8-19.


Temperature Method: This method requires that a woman take her temperature every morning to determine her basal body temperature (or BBT), which is lower before ovulation than after. By keeping track of BBT, she can figure out when she ovulates and when she is likely to become pregnant.


Cervical Mucus Method: This method requires that a woman learn to recognize the changes in the type and amount of vaginal discharge throughout her menstrual cycle. This differs from woman to woman, so individual instruction from a healthcare professional is critical. More mucus is produced as she becomes more fertile. She should track her discharge on a chart or calendar to become familiar with her safe and unsafe days to have unprotected intercourse. When used correctly, the typical failure rate of the cervical mucus method is 3% when used correctly.


Symptothermal Method: This is the most successful of the methods, as it is a combination of the previous three (therefore, a woman using this method would track her temperature and cervical mucus, as well as use a calendar method). Its typical failure rate is 0.4% when used correctly.


These methods are very convenient if you don’t want to depend on medications, implants, or barrier methods of birth control, which can be costly and have other side effects. However, these methods will likely be ineffective if:

  • Your period is irregular
  • You are a teenager
  • Your partner is not committed to the method, or you have multiple partners
  • You cannot or do not want to keep a record to determine safe days
  • You have an STI or unpredictable amounts of vaginal discharge
  • You do not want to abstain or use a different method of birth control for at least ten unsafe days per cycle
  • You take a medication that inhibits reading the aforementioned signs


Please see other posts from this series for information about barrier methods, intrauterine contraception, and hormonal methods.


Think you may be pregnant, or just want to know more? At Harmony, we offer free pregnancy testing, ultrasounds, and even STD testing and treatment at no cost to you. Click here to schedule an appointment.


This information is not meant to replace professional advice.



“Contraception.” Centers for Disease Control and Prevention. U.S. Department of Health & Human Services, 09 Feb. 2017. Web. 06 Mar. 2017.


“Fertility Awareness-Based Methods | (FAMs) Natural Birth Control.” Planned Parenthood. Planned Parenthood Federation of America Inc., 29 Nov. 2016. Web. 21 Mar. 2017.